It is often said the American Civil War was not fought over the issue of slavery, but over the right of states to secede. The assertion is initially appealing in that significant majorities in the northern states felt no need to go to war over the presence of slavery in the South, but a northern army was quickly mobilized when southern states seceded. This analysis, however, overlooks the decades-long debate over slavery, particularly the debate over its extension into the U.S. territories, which was the core disagreement that finally led to secession. Imagine two farmers who begin arguing about the ownership of a plot of land and find themselves coming to blows when they cannot agree on a subtle point in contract law. We would not say that they were fighting over a legal principle, but that they were fighting over the land. So too was the Civil War a struggle over slavery, not state sovereignty. Christopher Childers's masterly book The Failure of Popular Sovereignty traces the long argument that finally led to the Civil War. In the course of the account, the importance of slavery is revealed by the changing justifications offered by southern slaveholders in particular.
The central concern in both the North and the South was the extension of slavery into the territories. In time, four positions surfaced: (1) the federal government had authority to regulate and even outlaw slavery in the territories, (2) the government of a territory could regulate or outlaw slavery, (3) the citizens of a territory could regulate and even outlaw slavery, but only when applying for statehood, and (4) the federal government had an obligation actively to protect slavery in the territories until the territory became a state. Other positions also surfaced, but they tended to be opportunistic modifications of one of these four.
Strong precedents existed for the first of the four positions, even since before the ratification of the Constitution. The Northwest Ordinance (1787) prohibited slavery in the the territories north of the Ohio River and Thomas Jefferson's original draft of the Ordinance of 1784 regulating territories contained a stipulation that slavery in the territories would be prohibited after 1800. The stipulation was stripped from the ordinance, but only due the the sickness and absence of a single voter in the Confederation Congress. In 1820, the federal government passed the Missouri Compromise which prohibited slavery in the Louisiana territory north of 36' 30". It is noteworthy that during the discussion of the Missouri Compromise, John C. Calhoun, who later became the leading defender of the extension of slavery, endorsed the power of the federal government to prohibit it.
The Slave Power's early lack of concern over the federal power to restrict slavery changed as political sentiment against slavery grew in the country. Proslavery officials came to adopt a version of popular sovereignty that excluded federal authority over slavery in the territories. This headed off the extension of the Northwest Ordinance to the Orleans territory (Louisiana) and allowed the Arkansas territory to draft a slave code and be admitted as a slave state. The proslavery arguments held that the federal government should not dictate legislation to the citizens of the territories. To do so would be to treat them as colonies. This view was not based on any specific language in the Constitution. Indeed, Article Four, Section Three permitted the federal government to pass "needful rules and regulations" for the territories. Instead, the proslavery endorsement of popular sovereignty was based on a basic principle of American government that the people are capable of self-governance and that local authority should trump federal authority.
With the conquest of the Mexican territories, the proslavery position changed. The citizens of the territory of New Mexico were disposed to pass legislation prohibiting slavery, but to protect slavery, the Slave Power argued that the citizens of the territories were not politically mature enough for self-governance and that they could only prohibit slavery at the time they submitted an application for statehood. The Slave Power derided their own earlier position that allowed the territorial government authority over slavery, calling it "squatter sovereignty." It was thought by many that by insisting on "state sovereignty" instead, slaveholders would have time to emigrate to New Mexico and ensure that it would be admitted as a slave state.
By this time, Calhoun had recognized that even while the territorial governments might not be permitted to prohibit slavery, their slave codes (and social conditions) might effectively prohibit the emigration of slaves and slaveholders to the territories. What was necessary, according to Calhoun was the active protection of slave property by the federal government in the territories. Many southerners accepted Calhoun's analysis, but others, especially those in the upper South and border states, continued to adhere to "state sovereignty." Calhoun's position was effectively endorsed years after his death by the Supreme Court in Dred Scott v. Sandford (1857). More explicitly, Dred Scott rejected the constitutionality of the Missouri Compromise and held that the federal government had no authority to outlaw slavery in the territories, but by this time all four main positions regarding the extension of slavery were advanced by important political factions and various splinter positions were offered in an effort to reach a compromise over slavery.
Perhaps the most consistent position was held by the antislavery forces who argued that the federal government, empowered by the Constitution's Article Four, Section Three, could establish "needful rules and regulations" for the territories, that this included the prohibition of slavery, and that the frequent exercise of this power had established it in practice.
Among Childers's most interesting observations are the fine legal distinctions that were made by proponents of various versions of popular sovereignty. Proslavery radicals appeared to completely alter their views on popular sovereignty, moving through each of the four main positions to fit their interests in the extension of slavery. Steven A. Douglas, a more moderate politicians, retained his view that territorial governments could pass legislation regarding slavery (squatter sovereignty, if you will). Douglas argued that slavery could not exist where laws did not provide for its aid and protection. Douglas, consistent with his previous support for the Kansas-Nebraska Act, continued to argue for territorial sovereignty and against federal intervention in the territories. Douglas remained true to his commitment to the principle of self-determination of local communities. He also seemed to hope that this position would satisfy both southern and northern Democrats and maintain his party's political dominance.
Other politicians, particularly Lewis Cass attempted to satisfy both wings of the Democratic Party by issuing ambiguous statements on precisely when a territory was empowered to regulate slavery. His cagey approach nearly won him the presidency in 1848, but he was defeated by the Mexican War hero Zachery Taylor, who simply remained silent about the practicalities of popular sovereignty.
In general, The Failure of Popular Sovereignty is the story of a decades-long struggle over the extension of slavery. It provides an illuminating account of cross-cutting political considerations and evolving views about the constitutional protections afforded to slavery. Specific political figures involved in the formulation of the doctrine of popular sovereignty are vividly drawn, and the rising stakes in the debate lend growing excitement to the story. If there is a weakness to the history, it is the scant descriptions of the antislavery movement. A better understanding the internal debates within the Democratic Party over popular sovereignty would be achieved by placing the debate within a more vivid description of the larger political context. This would, of course, add a number of pages to the work, but the topic certainly deserves additional treatment.